Patent Document 1, for example, discloses a control apparatus for an internal combustion engine with a turbocharger. The conventional apparatus judges compressor surge of the turbocharger in accordance with the relationship between a pressure ratio of the upstream and downstream pressure of the compressor and an air flow amount passing through the compressor, the relationship between the above pressure ratio and engine speed.
Including the above-mentioned document, the applicant is aware of the following documents as a related art of the present invention.
[Patent Document 1] Japanese Laid-open Patent Application Publication No. 2001-342840
[Patent Document 2] Japanese Laid-open Utility Model Application Publication No. Hei 05-42642